In the pulp and paper industry, one process is the alkaline sulphate process, where lignin needs to be separated from the fibrous material. The chemicals which are used in this process, need to be recycled.

To better monitor each step in this process, from black liquor to green liquor, and finally to white liquor, LiquiSonic® analyzers from Sensotech work perfectly.

With LiquiSonic®, one can follow a quality control plan that will increase productivity.

APPLICATION

LiquiSonic® measuring technology allows the company real-time monitoring, green liquor generation, regulated and optimized, so that quality and precise results are born.

The base material in the liquor recycling process is black liquor. While burning an inorganic salt-rich smelt is formed, sediments form on the ground of the recovery boiler and have to be diluted by water or weak white liquor. The result of this process is green liquor, rich in Na2S and Na2CO3. The green liquor is often collec­ted in a separate stabilizing tank before it is clarified. While clarification of green liquor takes place, dregs have to be removed. The clarified green liquor is used for causticizing of regenerate NaOH.